NUMERICAL INVESTIGATION OF FLOW CHARACTERISTICS OF A NON-SLENDER LAMBDA WING UNMANNED AERIAL VEHICLE

In this paper, the low-speed aerodynamic performance of lambda wing with a chord length of c=210 mm and sweep angle of Λ =51°, thickness 3 mm, and beveled leading edges on the windward side with an angle of 58° is investigated numerically. Reynolds Average Navier Stokes (RANS) theorem equations with Spalart-Allmaras turbulence model were solved up to an angle of attack 45° for incompressible flow around the wing surface and, are compared to experiment to corralete simulation precision of computational fluid dynamic approaches. Detail about the aerodynamic performance of lambda wing including development and formation of the leading-edge vortex (LEV), the interaction of flow with the surface, flow separations, and stall are studied, presented, and discussed. LEV was started at 5°, vortex breakdown was observed at halfway along the leading edge at the angle of 20°, finally, by the time angle is 30°, bursting vortex gives a way to stall stage.